Skim over and Touch upon in passing

Skim over verb - Move or pass swiftly and lightly over the surface of.

Touch upon in passing and skim over are semantically related. In some cases you can replace phrase "Touch upon in passing" with "Skim over", this terms are similar.

Skim over and touch upon in passing are semantically related. Sometimes you can replace term "Skim over" with "Touch upon in passing", this terms are similar.