from
The Collaborative International Dictionary of English v.0.48
Almanac \Al"ma*nac\ (?; 277), n. [LL. almanac, almanach: cf. F.
almanach, Sp. almanaque, It. almanacco, all of uncertain
origin.]
A book or table, containing a calendar of days, and months,
to which astronomical data and various statistics are often
added, such as the times of the rising and setting of the sun
and moon, eclipses, hours of full tide, stated festivals of
churches, terms of courts, etc.
[1913 Webster]
{Nautical almanac}, an almanac, or year book, containing
astronomical calculations (lunar, stellar, etc.), and
other information useful to mariners.
[1913 Webster]