hypocotyl
noun
hy·po·cot·yl ˈhī-pə-ˌkä-tᵊl 
: the part of the axis of a plant embryo or seedling below the cotyledon see seedling illustration
Word History
Etymology
short for hypocotyledonous (stem), from hypo- + cotyledon + -ous
First Known Use
1880, in the meaning defined above
- on a roll
- on a rotating basis
- on a scale of
- on a shoestring budget
- on a small budget
- on a small/tight/shoestring budget
- on a sour note
- on a sudden
- on a suddenty
- on a tear
- on a tight budget
- on a trial basis
- on a whim
- on a wing and a prayer
- on a/the downswing
- on a/the knife-edge
- on about
- on account
- on account of
- on aggregate
- on air
- on all counts
- on all cylinders
- on all hands
- on all/several counts