breed animals or plants using parents of different races and varieties; "cross a horse and a donkey"; "Mendel tried crossbreeding"; "these species do not interbreed"
not tried or tested by experience; "unseasoned artillery volunteers"; "still untested in battle"; "an illustrator untried in mural painting"; "a young hand at plowing"
one of the quantities in a mathematical proportion
properly related in size or degree or other measurable characteristics; usually followed by `to'; "the punishment ought to be proportional to the crime"; "earnings relative to production"