early 15c., alteration of testicule (late 14c.), from Latin testiculus, diminutive of testis "testicle" (see testis). Old English had beallucas (see ballocks) and herþan, probably originally "leather bag" (compare heorþa "deer-skin"). The commonest slang terms for them in other languages are words that mean "balls," "stones," "nuts," "eggs."
testamentary
testate
testator
tester
testes
testicle
testicular
testify
testimonial
testimony
testis