予洗 is read as よせん (yosen) and means prewashing.
よせん
yosen
よあらい
prewashing
よてい
plans
preliminary contest
よやく
programming (e.g. a device)
よそう
expectation
よび
preparation
よほう
forecast
よち
foresight
よだん
prediction
よかん
to have a premonition
よき
よこく
trailer (film, TV)