Lectures one engaging in skilled activities (7)
I believe the answer is:
tirades
'lectures' is the definition.
(a tirade is an angry rant or lecture)
'one engaging in skilled activities' is the wordplay.
I cannot really see how this works, but
'one' could be 'i' (Roman numeral) and 'i' is found within the answer.
'activities' could be 'trades' (trade is a kind of activity) and 'trades' is found in the remaining letters.
No letters remain.
This may be the basis of the clue (or it may be nonsense).
Can you help me to learn more?
(Other definitions for tirades that I've seen before include "Speeches of violent denunciation" , "stormy blasts" , "Invective" , "Astride (anag) - diatribes" , "Abusive words" .)