patch vs touch on

patch is a noun but touch on is not a noun.

Word	Noun	Adjective	Verb	Adverb
patch	Yes	No	Yes	No
touch on	No	No	Yes	No

As verbs, touch on is a hypernym of patch; that is, touch on is a word with a broader meaning than patch:

patch: mend by putting a patch on
touch on: restore by replacing a part or putting together what is torn or broken

Other hypernyms of patch include bushel, doctor, fix, furbish up, mend, repair, restore.

As verbs, touch on is a hypernym of patch; that is, touch on is a word with a broader meaning than patch:

patch: repair by adding pieces
touch on: restore by replacing a part or putting together what is torn or broken

Other hypernyms of patch include bushel, doctor, fix, furbish up, mend, repair, restore.

patch (noun)	touch on (noun)
a piece of cloth used as decoration or to mend or cover a hole
sewing that repairs a worn or torn hole (especially in a garment)
a protective cloth covering for an injured eye
a connection intended to be used for a limited time
a piece of soft material that covers and protects an injured part of the body
a small contrasting part of something
a short set of commands to correct a bug in a computer program
a small area of ground covered by specific vegetation
a period of indeterminate length (usually short) marked by some action or condition

patch (verb)	touch on (verb)
mend by putting a patch on	restore by replacing a part or putting together what is torn or broken
repair by adding pieces	have an effect upon
to join or unite the pieces of	refer to or discuss briefly
provide with a patch; also used metaphorically	be relevant to