The traditional Boston accent is non-rhotic, particularly in the early 1900s. Recent studies have shown that younger speakers tend to use more of a rhotic accent than older speakers from the Boston region. The Boston accent is pronounced with a “broad A”. The letter "r" is dropped only in certain words like 'car' and 'hard'. For example, a person might “pahk the cah in Hahvahd yahd.”
Lexicon
Some words used in the Boston area are:
blinkers
turn signals on a car (also U.K., Australia and New Zealand). The Massachusetts Department of Transportation has displayed signs reminding motorists to "Use Yah Blinkah", a phonetic representation of the phrase as spoken with a Boston accent.
drinking fountain, pronounced "bubblah". This term is also used in Wisconsin and Australia.
frappe
a beverage mixed with milk and ice cream, a.k.a. milkshake (in most other places), or if in Rhode Island (and especially if coffee flavored), called a "cabinet"
Hoodsie
A small cup of ice cream, the kind that comes with a flat wooden spoon (from HP Hood, the dairy that sells them.) Also (very offensive slang), a teenage girl. Elsewhere occasionally known as a dixie cup.
jimmies
Chocolate ice cream sprinkles Also common in the Philadelphia area.
means something akin to "great" either realistically or sarcastically. Also spelled 'pissa'. This is from the word "pisser" with a Boston accent, but used as an adjective. Occasionally combined with "wicked" to yield "wicked pissah".
Generally means "very" or "super" and is used as an adverb. "That hockey game was wicked awesome!" It can also be used to infer tones and moods, for example, "Ugh, that guy is wicked slow."
spa
A convenience store that has tonic on tap and (usually) sells sandwiches.
↑Bernd Kortmann; Edgar W Schneider, A Handbook of Varieties of English: A Multi-Media Reference Tool (Berlin; New York: Mouton de Gruyter, 2005), p. 270