Touch upon
Definition 1 of 1
Pro Tip 1/3Briefness
The phrase implies only a quick or partial reference to a bigger topic. 
During the meeting, we'll touch upon the budget but focus mainly on the project plan.
Pro Tip 2/3Subtlety
Use it when wanting to mention a topic without going into depth or when skirting around sensitive issues. 
He touched upon his past struggles, without providing too many personal details.
Pro Tip 3/3Indirectness
'Touch upon' can introduce a subject indirectly, hinting rather than stating. 
The poet touched upon themes of loss in her verses.