Pitch, of course, can be sticky (6)
I believe the answer is:
wicket
'pitch of course' is the definition.
The answer and definition can be both man-made objects as well as being singular nouns.
Maybe you can see an association between them that I don't see?
I can't explain the remainder of the clue.
Can you help me to learn more?
(Other definitions for wicket that I've seen before include "may be secured by a catch" , "One of the 21 acrosses" , "that first-class delivery may take" , "Three stumps and two bails" , "Small door or gate" .)