The main verb ÇÜ adi `beat, strike' may be used as a verbalizer to create verbs whose actions are considered pejorative, inappropriate, or unpleasant, i. e. the speaker disapproves of the action in some way.
Other examples are:
Note the contrast between ÇÜ adi and ½ýá pannu as a regular verbalizer for `ordinary' (non-pejorative) actions in the constructions above, where Ø½Ô¯ ÇÜ boor-adi and ´Ô¤½Õ ÇÜ kaappi adi using the English borrowed verbs `to bore' and `to copy' (as if they were nouns) means to do something unpleasant or wrong, whereas Ø½Ô¯ ½ýá boor-pannu and ´Ô¤½Õ ½ýá kaappi pannu mean to make legitimate and proper holes, copies, etc.
In some other combinations, however, ÇÜ adi is not pejorative.
ÇÜ adi is normal in this phrase because of the action of tapping the telegraph key.