Tidal floods? They are tedious (5)
I believe the answer is:
bores
'tidal floods?' is the definition.
The answer and definition can be both man-made objects as well as being plural nouns.
Maybe they are linked in a way I don't understand?
I can't explain the remainder of the clue.
Can you help me to learn more?
(Other definitions for bores that I've seen before include "Drills or wearies" , "Dull tedious talkers" , "Makes a hole with a pointed tool" , "Tedious people or drills" .)