'touch on' definitions:

Definition of 'touch on'

From: WordNet
verb
Refer to or discuss briefly
verb
Be relevant to; "There were lots of questions referring to her talk"; "My remark pertained to your earlier comments" [syn: refer, pertain, relate, concern, come to, bear on, touch, touch on, have-to doe with]
verb
Restore by replacing a part or putting together what is torn or broken; "She repaired her TV set"; "Repair my shoes please" [syn: repair, mend, fix, bushel, doctor, furbish up, restore, touch on] [ant: break, bust]
verb
Have an effect upon; "Will the new rules affect me?" [syn: affect, impact, bear upon, bear on, touch on, touch]

Definition of 'touch on'

From: GCIDE
  • touch on \touch" on\, v. t. To mention briefly, or in passing. [PJC]