Mid 17th century: from the phrase for the name's sake.

• sake from Old English:

  Old English sacu ‘contention, crime’ is from a Germanic source, from a base meaning ‘affair, legal action, thing’. The phrase for the sake of was not in Old English and may be from Old Norse. It was originally a legal expression. Sake remains hidden in the language in the words forsake (Old English), which originally meant ‘renounce, refuse’; keepsake (late 18th century) something kept for the sake of the giver; and namesake (mid 17th century) which may be a shortening of ‘for one's name sake’. The Japanese rice wine sake, pronounced with two syllables, is simply the Japanese word for ‘alcohol’. See also seize