syn·er·gid 
(sĭ-nûrjĭd, sĭnər-)
(sĭ-nûrjĭd, sĭnər-)n.
One of two small cells lying near the egg in the mature embryo sac of a flowering plant.
[New Latin synergida, from Greek sunergos, working together; see SYNERGISM.]
- on the hoof
- on the horns of a dilemma
- on the house
- on the increase
- on the inside
- on the job
- on-the-job
- on the level
- on the line
- on the loose
- on the make
- on the march
- on the market
- on the mend
- on the money
- on the move
- on the nose
- on the off chance
- on the onehand
- on the order of
- on the other hand
- on the outs
- on the part of
- on the prowl
- on the qui vive