〜（が）ごとし／〜ごとく／〜ごとき

Meaning

An archaic literary expression for metaphor or illustration, "like ~." Used differently by position: 「ごとし」 at the end of a sentence, 「ごとく」 adverbially, and 「ごとき」 modifying a noun.

Examples

「光陰矢のごとし」と言うように、月日が経つのは早い。 As the saying goes, "Time flies like an arrow" — how quickly the days pass.
彼は氷のごとく冷たい目で相手を見据えた。 He fixed his gaze on his opponent with eyes as cold as ice.
彼のごとき優れた人物に、二度と出会えないだろう。 I doubt I will ever meet another person of his caliber.