amphigastrium /am-fi-gasˈtri-əm/

A scale-like leaf on the ventral side of some liverworts

• on the run
• on the safe side
• on the same wavelength as
• on the scale of
• on the shady side of
• on the shelf
• on the shop floor
• on the short side
• on the side
• on the side of the angels
• on the slate
• on the sly
• on the spin
• on the spot
• on-the-spot
• on the spur of the moment
• on the square
• on the starboard beam
• on the starboard bow
• on the stocks
• on the street
• on the streets
• on the strength
• on the strength of
• on the stroke