Low nest regularly seen in pines (5)
I believe the answer is:
moons
'pines' is the definition.
(both can mean to show infatuation)
'low nest regularly seen' is the wordplay.
'low' becomes 'moo' ('moo' can be a synonym of 'low').
'regularly seen' indicates alternate letters.
The alternate letters of 'nest' are 'ns'.
'moo'+'ns'='MOONS'
'in' acts as a link.
(Other definitions for moons that I've seen before include "Orbiting bodies" , "carry on" , "Natural satellites" , "months" , "Satellites of planets" .)