・by twos and threes 三々五々.

・one by one 一つ一つ, 一人ずつ.

・It was getting colder minute by minute [by the minute]. 刻々寒くなっていった.

・The snow fell flake by flake. 雪がひらひらと落ちてきた.

15a [程度・度合い] 〈幾ら〉だけ, …の程度まで, …の差で.

・too many by one 一つだけ多すぎて.

・by a long way はるかに.

・reduce by half [a third, two-thirds] 半分[^１/_３, ^２/_３]だけ減らす.

・miss by a minute [second] 1 分[秒]だけ遅れる, ほんのちょっとで間に合わない.

・be short by 2 feet＝be 2 feet short 2 フィートだけ短い.

・win by a boat's length [by a head] 1 艇身の差[馬首だけの差]で勝つ.