a person or thing that takes or can take the place of another
an athlete who plays only when a starter on the team is replaced
put in the place of another; switch seemingly equivalent items; "the con artist replaced the original with a fake Rembrandt"; "substitute regular milk with fat-free milk"
be a substitute; "The young teacher had to substitute for the sick colleague"; "The skim milk substitutes for cream--we are on a strict diet"
act as a substitute; "She stood in for the soprano who suffered from a cold"
make a counterattack and return like for like, especially evil for evil; "The Empire strikes back"; "The Giants struck back and won the opener"; "The Israeli army retaliated for the Hamas bombing"
precisely and clearly expressed or readily observable; leaving nothing to implication; "explicit instructions"; "she made her wishes explicit"; "explicit sexual scenes"