Lofty is intoxicated (4)
I believe the answer is:
high
This clue is a double definition.
'lofty' is the first definition.
(similar in meaning)
'is intoxicated' is the second definition.
(similar in meaning)
(Other definitions for high that I've seen before include "Eminent; lofty" , "Outstanding feature" , "In slang, under the influence of drugs" , "Shrill" , "At altitude" .)