DECADAL
Etymology
Adjective
decadal (not comparable)
Of or related to the number ten.
Of or related to a decade, in its various senses.
Usage notes
Although decade may be taken as any group of ten years, it is commonly restricted to the informal ten-year periods of the calendar whose last digits run from 0 to 9. In such contexts, decadal refers to such calendar periods while decennial etc. refer to ten-year periods in other contexts.
Synonyms
• (in some contexts): See decennial
Source: Wiktionary
Dec"a*dal, a.
Definition: Pertaining to ten; consisting of tens.
Source: Webster’s Unabridged Dictionary 1913 Edition