diff --git a/src/bipsea/bip85.py b/src/bipsea/bip85.py
index c5d8269..9ecf4bd 100644
--- a/src/bipsea/bip85.py
+++ b/src/bipsea/bip85.py
@@ -23,7 +23,7 @@
     "dice": "89101'",
     "drng": "0'",
     "hex": "128169'",
-    "words": "39'",
+    "mnemonic": "39'",
     "wif": "2'",
     "xprv": "32'",
 }
@@ -69,7 +69,7 @@ def apply_85(derived_key: ExtendedKey, path: str) -> Dict[str, Union[bytes, str]
 
     entropy = to_entropy(derived_key.data[1:])
 
-    if app == APPLICATIONS["words"]:
+    if app == APPLICATIONS["mnemonic"]:
         language_index, n_words = indexes[:2]
         n_words = int(n_words[:-1])  # chop ' from hardened derivation
         if n_words not in N_WORDS_META.keys():
diff --git a/src/bipsea/bipsea.py b/src/bipsea/bipsea.py
index e904877..0470567 100644
--- a/src/bipsea/bipsea.py
+++ b/src/bipsea/bipsea.py
@@ -113,19 +113,19 @@ def bip39_cmd(from_, to, input, number, passphrase, pretty):
     if (from_ == "random" and input) or (from_ != "random" and not input):
         raise click.BadOptionUsage(
             option_name="--from",
-            message="`--from words` requires `--input STRING`, `--from rand` forbids `--input`",
+            message="`--from [anything but 'rand']` requires `--input`, `--from rand` forbids `--input`",
         )
     language = ISO_TO_LANGUAGE.get(from_)
     if language or from_ == "any":
-        if to == "words":
+        if to == "mnemonic":
             raise click.BadOptionUsage(
                 option_name="--to",
-                message="`--to words` incompatible with `--from LANGUAGE`",
+                message="f`--to {from_}` incompatible with `--from [anything but 'rand']`",
             )
         words = normalize_list(re.split(r"\s+", input), lower=True)
         if language and not verify_seed_words(words, language):
             raise click.BadParameter(
-                f"Unexpected {language} words from `--input` ({' '.join(words)}) or bad checksum.",
+                f"--input mnemonic not in {from_} or has bad checksum.",
                 param_hint="--input",
             )
         if from_ == "any":
@@ -176,7 +176,7 @@ def bip39_cmd(from_, to, input, number, passphrase, pretty):
 @click.option(
     "-a",
     "--application",
-    default="words",
+    default="mnemonic",
     required=True,
     type=click.Choice(APPLICATIONS.keys()),
 )
@@ -184,7 +184,7 @@ def bip39_cmd(from_, to, input, number, passphrase, pretty):
     "-n",
     "--number",
     type=int,
-    help="Length of output in bytes, chars, or words, depending on the application.",
+    help="Length of output in bytes, chars, or words, depending on --application.",
 )
 @click.option(
     "-i",
@@ -209,7 +209,7 @@ def bip39_cmd(from_, to, input, number, passphrase, pretty):
     "-t",
     "--to",
     type=click.Choice(ENTROPY_TO_VALUES),
-    help="Mnemonic language for `--application words`.",
+    help="Output language for `--application mnemonic`.",
 )
 def bip85_cmd(application, number, index, special, input, to):
     if not input:
@@ -250,15 +250,15 @@ def bip85_cmd(application, number, index, special, input, to):
     path += f"/{app_code}"
 
     if to:
-        if application != "words":
+        if application != "mnemonic":
             raise click.BadOptionUsage(
                 option_name="--to",
-                message="--to requires `--application words`",
+                message="--to requires `--application mnemonic`",
             )
     else:
         to = "eng"
 
-    if application == "words":
+    if application == "mnemonic":
         language = ISO_TO_LANGUAGE[to]
         code_85 = next(i for i, l in INDEX_TO_LANGUAGE.items() if l == language)
         path += f"/{code_85}/{number}'/{index}'"
diff --git a/tests/test_cli.py b/tests/test_cli.py
index e89eaa2..7527c0c 100644
--- a/tests/test_cli.py
+++ b/tests/test_cli.py
@@ -72,7 +72,7 @@ def test_seed_option_sensitivity(runner, language, vectors):
             result = runner.invoke(cli, cmd)
             if suffix == ".":
                 assert result.exit_code != 0
-                assert "Unexpected" in result.output
+                assert lang_code in result.output
             else:
                 assert result.exit_code == 0
                 result_xprv = result.output.strip().split("\n")[-1]
@@ -199,7 +199,7 @@ def test_entropy_bip39(runner, vector):
     xprv = vector["master"]
     n_words = vector["mnemonic_length"]
     result = runner.invoke(
-        cli, ["entropy", "-a", "words", "--input", xprv, "-n", n_words]
+        cli, ["entropy", "-a", "mnemonic", "--input", xprv, "-n", n_words]
     )
     assert result.exit_code == 0
     words = result.output.strip()
@@ -210,7 +210,7 @@ def test_entropy_bip39(runner, vector):
 def test_entropy_bip39_languages(runner, iso):
     xprv = MNEMONIC_12["xprv"]
     result = runner.invoke(
-        cli, ["entropy", "-a", "words", "--input", xprv, "-n", 12, "-t", iso]
+        cli, ["entropy", "-a", "mnemonic", "--input", xprv, "-n", 12, "-t", iso]
     )
     assert result.exit_code == 0
     words = result.output.strip()