ETYMOLOGY
from Latin ientaculum (breakfast); (from ientare (to breakfast)) + -ar
EXAMPLE
“… I wonder that you did not, under this head, acquaint us with that wise injunction, which you have caused to be promulgated within your dominions, against the consumption of tea and coffee; a fashionable vice, which tends only to squandring away money, and mispending the morning, since (as you once ingeniously express’d it) nothing more can be expected from those jentacular confabulations. …”
From: Terræ-filius; or, the secret history of the University of Oxford
By Nicholas Amhurst, 1721
Lexicophilia 