Emphasised (8)
'emphasised' is the definition.
(similar in meaning)
This is all the clue.
(Other definitions for stressed that I've seen before include "Drew attention to" , "Feeling tension" , "Brought out" , "Hassled, under pressure" , "Strained or emphasised" .)
'emphasised' is the definition.
(underscoring is a kind of emphasizing)
This is the entire clue.
(Another definition for underscored that I've seen is " Stressed".)