Goggles regularly covering left eye up (4)
I believe the answer is:
ogle
'eye up' is the definition.
(I've seen this before)
'goggles regularly covering left' is the wordplay.
'regularly' means one should take alternating letters (regularly take one letter, leave next etc.).
'covering' indicates putting letters inside.
'left' becomes 'l' (common abbreviation).
The alternate letters of 'goggles' are 'oge'.
'oge' placed around 'l' is 'OGLE'.
(Other definitions for ogle that I've seen before include "Give the glad eye" , "Cast flirtatious glance at" , "Make eyes at" , "Look at lecherously" , "Stare lewdly" .)