Words familiar to those of a certain age often baffle those of another. Take "Toonerville." In recounting last month's 50th anniversary of the last run of the Connecticut Avenue streetcar line, we referred to an extension of the line from Chevy Chase Lake to Kensington as a Toonerville.

What, one reader in her thirties asked, is -- or was -- a Toonerville?

It was the Toonerville Trolley, pictured at the right, an ancient and decrepit trolley car that jounced on rickety tracks drawn across America's comics pages from about 1917 until creator Fontaine Fox retired, a rich man, in 1955. It was time to go. For the Toonerville's abandonment more or less coincided with the death throes of electric streetcars in most American cities.

But Toonerville was more than a trolley. It and its community of vacant lots and rustic storefronts along with the characters who were featured -- the Skipper, Powerful Katrinka and practical joker Lem Wortle among them -- were a metaphor for an utterly informal and often outrageous semirural life style.

It was nothing you'd have found in urbane central Washington. But Washington had its share of archetypical Toonerville trolleys, routes on the city's outskirts unaffiliated with the downtown streetcar system, using cars not too unlike the one pictured here.

For example, there was Baltimore & Washington Transit, a line that never got farther than Takoma Park and disappeared in 1937; the Washington, Spa Spring and Gretta Railroad, bearing community names lost in the mists of time, that stretched 8 1/2 miles along Bladensburg Road and that, under another name, expired in 1921; and there was one line that ran a scant 0.72 mile on Pennsylvania Avenue SE. From 1905 until 1923, its dinky cars met the mainline cars from downtown at Barney Circle and carried their passengers across what is now Sousa Bridge to Minnesota Avenue.