A helpmate is a helpful partner, and in real use that partner is nearly always a wife. The word feels old, literary, or church-like. Almost nobody says it in ordinary modern English; we say partner, spouse, or wife. Though actually the history is a mix-up: an older phrase help meet meant “a helper who is right for him.” That became helpmeet, and people later heard it as help + mate (a partner). So the spelling helpmate looks neat, but it was reshaped by the ear, not built as a fresh compound. When you do meet it, it often praises the wife as the one who stands beside the man and works with him — a picture many readers now find dated.

賢內助（偏指妻子，舊式、書面）