Actor, regularly loud, very very immodest and egotistical at the outset (6)
I believe the answer is:
luvvie
'actor' is the definition.
(I've seen this before)
'regularly loud very very immodest and egotistical at the outset' is the wordplay.
'regularly' indicates alternate letters (regularly take one letter, leave next etc.).
'very' becomes 'v' (abbreviation).
'very immodest' becomes 'vi' (this might be a standard abbreviation of which I'm unaware).
'and' says to put letters next to each other.
'at the outset' says to take the initial letters.
The initial letter of 'egotistical' is 'e'.
The alternating letters of 'loud' are 'lu'.
'lu'+'v'+'vi'+'e'='LUVVIE'
Can you help me to learn more?
(Other definitions for luvvie that I've seen before include "affected actor, perhaps" , "18, 5 [LAURENCE OLIVIER] for example" , "Theatrical type" .)