Noun
A haphazard shot with a firearm, taken with careless aim, often fired at a random target.
A shot taken from a hidden stakeout.
By analogy, insulting or hurtful words carelessly or randomly said; opportunistic attack, especially criticism.
Source: en.wiktionary.orgpot-shot
In an interview with a journalist, you look petty taking the pot shot but in a slick ad you can really do damage - including unfair damage - from afar. It is not that much different than waging a war by a drone than by hand-to-hand combat. Greta Van Susteren