組合せ
くみあわせ · kumiawase · JLPT N2 · noun
combination
組 (kumi, group) + 合わせ (awase, matching up) = grouping items together to match up
組合せ literally means 'group matching-up.' Kumi is a set or team; awase is putting things together. Together they mean a combination of items chosen from a set.
合 — 乛 (lid/roof) + 口 (mouth)
Originally a pictograph of a lidded vessel — a cover (亼) closing over an opening (口) — giving the core sense of 'come together, join, fit.' From 'fit/match' it extended to 'combine, unite, agree' and to measure-word uses. The reading hé reflects this 'joining' meaning.