just under; a little less than; just short of
駅まで歩いて十分足らずだ。
It takes less than ten minutes to walk to the station.
百円足らずのお菓子を子供に渡した。
She handed a snack worth less than a hundred yen to the child.
三十分足らずで問題をすべて解いてしまった。
He solved all the problems in less than thirty minutes.