Obsolete spelling of yeast

plural of yest

The day immediately before today; one day ago. / (figuratively) The past, often in terms of being outdated.

On the day before today. / (informal) As soon as possible.

(poetic) Past years; time gone by; yore. / (rare) Last year.

(informal, chiefly in the negative) To be new, naive, innocent, inexperienced, or easily deceived.

(chiefly archaic, poetic or Scotland) The night before.

plural of yestreen

(archaic) Last night.

(archaic) A preceding night.