[1] : The Collaborative International Dictionary of English v.0.48

roger \rog"er\, n. from a proper name roger.
   a black flag with white skull and crossbones, formerly used
   by pirates; -- called also jolly roger and pirate flag.
   webster 1913 suppl. +pjc
see also:
jolly roger pirate flag 

[2] : WordNet (r) 2.0

jolly roger
     n : a black flag bearing a white skull and crossbones; indicates
         a pirate ship syn: black flag, pirate flag
see also:
black flag pirate flag 

[3] : Moby Thesaurus II by Grady Ward, 1.0

40 moby thesaurus words for "jolly roger":
   dannebrog, old glory, star-spangled banner, stars and stripes,
   union flag, union jack, and blue, banderole, banner, banneret,
   black flag, blue ensign, bunting, burgee, coachwhip, colors,
   ensign, flag, gonfalon, gonfanon, guidon, house flag, jack,
   long pennant, merchant flag, national flag, oriflamme, pennant,
   pennon, pennoncel, red, red ensign, royal standard, signal flag,
   standard, streamer, swallowtail, tricolor, vexillum, white

Jolly Roger >> J Words
Jolly Roger, definition of term: Jolly Roger
jolly+roger_pag1.html

Roger >> R Words
Roger, definition of term: Roger
roger_pag1.html

Jolly >> J Words
Jolly, definition of term: Jolly
jolly_pag1.html