Discussion Groups / English Usage / January 2004

Too late for OED1 or SOED3 (1956 revision, 1970 printing), still missing in
NSOED=SOED4 (1993) and SOED5 (2003), MWCD11 (2003), Chambers (2003), AHD4
(2000).

Anyone _might_ have used it, since it follows fairly a normal English
morphology pattern, although has been an upswing in young, pseudo-hip usage
of the -inous and -udinous forms in that last 10-20 years.  The increased
use of "attitude" and "'tude" may well have fueled a felt need for such an
adjective.

BTW, "attitudini[sz]e" is more than 400 years old.