There doesn't seem to be a definition, does there?
The definition is supposed to be either the first or the last in the clue. The Lord's speech? Poor clue
'Trout' refers to 23 A in Times Jumbo Cryptic 928, which I queried earlier.
The clue is -
Swimmer that strong needs to produce air (5)
t-o-t
'Trout' seems the likeliest answer, though the mention of 'strong' seems irrelevant.