Subscribe like Abraham Lincoln, initially? That's notable (6)
I believe the answer is:
signal
'notable' is the definition.
(I've seen this before)
'subscribe like abraham lincoln initially?' is the wordplay.
'subscribe' becomes 'sign' (synonyms).
'like abraham' becomes 'a' (I am not sure about this - if you are sure you should believe this answer much more).
'initially?' suggests taking the first letters (I've seen 'initially' mean this).
The initial letter of 'lincoln' is 'l'.
'sign'+'a'+'l'='SIGNAL'
'that's' acts as a link.
Can you help me to learn more?
(Other definitions for signal that I've seen before include "Important; cue" , "Communication by sign" , "way to communicate" , "Gesture giving information or command" , "Important; communication" .)