blow up shipping docks to intimidate British merchants and military.
Sounds more like good guerrilla warfare than terrorism to me. If the supply lines of your much larger enemy have a chokepoint (as it was during the Revolutionary War; the enemy depended on naval transport for everything) that's exactly what you want to target, mainly for the material and personnel effect (the latter assuming most of the people working in the shipyard accepting British transport were on the side of the enemy). Psychological effects at most are a tertiary bonus, if you were lucky...blowing up a dock in the Revolutionary War would be a really inefficient way to instill enough fear in the public of Great Britain to change public support of a war.
Modern examples of the difference:
Terrorism: Flying jetliners into buildings in a way sure to get good media coverage and keeping the threat of the possibility of it happening again ambiguous.
Guerrilla tactics: Attacking supply lines of your enemy in Afghanistan, rather then wasting your personnel in a head-on attacks against a much stronger enemy.
Guerrilla warfare != Terrorism