Unemotional drunken sot, I see (5)
I believe the answer is:
stoic
'unemotional' is the definition.
(similar in meaning)
'drunken sot i see' is the wordplay.
'drunken' indicates anagramming the letters.
'see' becomes 'C' (the word for the letter, according to Chambers).
'sot' with letters rearranged gives 'sto'.
'sto'+'i'+'c'='STOIC'
(Other definitions for stoic that I've seen before include "Someone seemingly indifferent to pleasure or pain" , "One able to endure hardship; philosopher" , "One patient under misfortune" , "One who endures hardship uncomplainingly" , "Long-suffering type; follower of Zeno" .)