Adjective

(en adjective)

Hard-working, diligent or regular (in attendance or work); industrious.

* 1831 , , The Surgeon's Daughter , ch. 2:

He was officious in the right time and place, quiet as a lamb when his patron seemed inclined to study or to muse, active and assiduous to assist or divert him whenever it seemed to be wished.

* 1880 , , Washington Square , ch. 33:

He died after three weeks' illness, during which Mrs. Penniman, as well as his daughter, had been assiduous at his bedside.

* 1917 , , "Bill the Bloodhound" in The Man With Two Left Feet and Other Stories :

A good deal of assiduous attention had enabled Henry to win this place in her affections.

* 2009 , Will Pavia , " Allen Klein, accountant turned manager of the Beatles, dies at 77," The Times (UK), 6 July:

Klein rose to prominence in the 1960s by assiduous application of accounting methods to the music industry.

Adjective

(-)

Happening once every year.

* {{quote-magazine, date=2013-06-29, volume=407, issue=8842, page=29, magazine=(The Economist)

, title= Unspontaneous combustion , passage=Since the mid-1980s, when Indonesia first began to clear its bountiful forests on an industrial scale in favour of lucrative palm-oil plantations, “haze” has become an almost annual occurrence in South-East Asia. The cheapest way to clear logged woodland is to burn it, producing an acrid cloud of foul white smoke that, carried by the wind, can cover hundreds, or even thousands, of square miles.}}

Of, for, or relating to a whole year, often as a recurring cycle; determined or reckoned by the year; accumulating in the course of a year; performed, executed, or completed over the course of a year. See also circannual.

(botany, of a plant) Having a life cycle that is completed in only one growing season; e.g. beans, corn, marigold. See in Wikipedia. Compare biennial, perennial.

(entomology) Living or lasting just one season or year, as certain insects or insect colonies.