OCCURRING
OCCUR
happen, hap, go on, pass off, occur, pass, fall out, come about, take place
(verb) come to pass; “What is happening?”; “The meeting took place off without an incidence”; “Nothing occurred that seemed important”
occur, come
(verb) come to one’s mind; suggest itself; “It occurred to me that we should hire another secretary”; “A great idea then came to her”
occur
(verb) to be found to exist; “sexism occurs in many workplaces”; “precious stones occur in a large area in Brazil”
Source: WordNet® 3.1
Verb
occurring
present participle of occur
Noun
occurring (plural occurrings)
An instance of something occurring; an event or happening.
Adjective
occurring (not comparable)
(in combination) That occurs in a specified manner.
naturally occurring macromolecules
Source: Wiktionary
OCCUR
Oc*cur", v. i. [imp. & p. p. Occurred(); p. pr. & vb. n. Occurring.]
Etym: [L. occurrere, occursum; ob (see Ob-) + currere to run. See
Course.]
1. To meet; to clash. [Obs.]
The resistance of the bodies they occur with. Bentley.
2. To go in order to meet; to make reply. [Obs.]
I must occur to one specious objection. Bentley.
3. To meet one's eye; to be found or met with; to present itself; to
offer; to appear; to happen; to take place; as, I will write if
opportunity occurs.
In Scripture, though the word heir occur, yet there is no such thing
as "heir" in our author's sense. Locke.
4. To meet or come to the mind; to suggest itself; to be presented to
the imagination or memory.
There doth not occur to me any use of this experiment for profit.
Bacon.
Source: Webster’s Unabridged Dictionary 1913 Edition