Masculine gender is one of three grammatical genders in Greek.
It doesn't always correspond to biological sex.
Indicators of masculine:
• Article: ὁ (singular), οἱ (plural)
• Second declension -ος nouns are usually masculine
• Many agent nouns and professions are masculine
• Adjectives show masculine forms: -ος (nom sg)
Some words are masculine despite meaning:
• ὁ ποταμός (river)
• ὁ ἥλιος (sun)
• ὁ πόλεμος (war)
Adjectives and articles must agree with their noun's gender.
Examples from Texts
Here are some words showing the masculine gender in actual Greek texts:
φιλοστοργότατον
φιλόστοργος
loving tenderly, affectionate
noun
accusative
masculine
singular
ἐπηβόλους
ἐπήβολος
having reached, achieved
noun
accusative
masculine
plural
σαφεῖ
σαφής
clear, plain, distinct
noun
dative
masculine
singular
σαβακόν
σαβακός
feeble
noun
accusative
masculine
singular
λῴστω
λῷστος
more desirable, more agreeable, better
noun
genitive
masculine
singular
βορειοτέροις
βόρειος
from the quarter of the north wind, northern
noun
dative
masculine
plural
δυσεντερικοῦ
δυσεντερικός
afflicted with dysentery
noun
genitive
masculine
singular
μεγαλήγορε
μεγαλήγορος
talking big, vaunting
noun
vocative
masculine
singular