Happy if only I, on a regular basis, will get flowers (8)
I believe the answer is:
gladioli
'flowers' is the definition.
(I've seen this before)
'happy if only i on a regular basis' is the wordplay.
'happy' becomes 'glad' (similar in meaning).
'on a regular basis' means one should take alternating letters.
'if'+'only'+'i'='ifonlyi'
The alternate letters of 'ifonlyi' are 'ioli'.
'glad'+'ioli'='GLADIOLI'
'will get' is the link.
(Other definitions for gladioli that I've seen before include "Garden flowers of the iris family" , "bloomers!" , "Tall garden flowers" , "Flowers with sword-shaped leaves" , "Plant with brightly coloured, funnel-shaped flowers" .)