Of great height (5)
'of great height' is the definition.
(I've seen this before)
This is the entire clue.
(Other definitions for tall that I've seen before include "Remarkable" , "Unbelievable" , "Above average height" , "High in stature" , "Like giants" .)
(Other definitions for lofty that I've seen before include "Of majestic height" , "Haughty" , "Soaring" , "Such ideals" , "Noble, elevated" .)