Remove or be removed by washing; also, cause to fade by laundering. For example, Give it to me; I'll wash out that stain, or The bleach has really washed out that bright print. [Mid-1700s]
Wear away or be worn away by the flow of water, as in The river rose and washed out the dam, or The road has completely washed out. [Mid-1700s]
Deplete or be depleted of energy, as in Working on her feet all day just washed her out, or I just washed out after that long tennis match. [Mid-1800s]
Eliminate or be eliminated as unsatisfactory, as in He washed out of medical school after just one year, or After only two months as chairman I washed out. [Colloquial; early 1900s]
Cancel owing to bad weather, as in The picnic was washed out. [Colloquial; early 1900s] Also see washed out.