• vi. 發生；出現；存在

oc-,相對，對著的，-cur,跑，詞源同current,course.即跑到一起的，引申詞義遇到，出現，發生。

occur

occur: [16] Etymologically, occur means ‘run towards’. It was borrowed from Latin occurrere, a compound verb formed from the prefix ob- ‘towards’ and currere ‘run’ (source of English course, current, etc). This had the sense ‘run to meet’, hence simply ‘meet’, which survived into English: ‘The whole multitude might freely move … with very little occurring or interfering’, Richard Bentley, Boyle Lectures 1692. But ‘meeting’ also passed into ‘presenting itself’, ‘appearing’, and hence ‘happening’ – from which the main present-day meaning of English occur comes.
=> course, current

occur (v.)

1520s, "meet, meet in argument," from Middle French occurrer "happen unexpectedly" or directly from Latin occurrere "run to meet, run against, befall, present itself," from ob "against, toward" (see ob-) + currere "to run" (see current (adj.)). Sense development is from "meet" to "present itself" to "appear" to "happen" ("present itself in the course of events"). Meaning "to come into one's mind" is from 1620s. Related: Occurred; occurring.

1. If these drugs are stopped abruptly then some withdrawal symptoms may occur.

如果突然停服這些藥，則可能出現一些戒斷癥狀。

來自柯林斯例句

2. Keep a pad handy to jot down queries as they occur.

手邊放一本便箋簿，以便有問題時隨時記下。

來自柯林斯例句

3. Nitrates are chemicals that occur naturally in water and the soil.

硝酸鹽是水和土壤中自然存在的化學物質。

來自柯林斯例句

4. Emergency cooling systems could fail and a reactor meltdown could occur.

緊急冷卻系統有可能失靈，核反應堆有可能發生堆芯熔毀。

來自柯林斯例句

5. Unless you respect other people's religions, horrible mistakes and conflict will occur.

如果不尊重別人的宗教信仰，就會禱下大錯，釀成沖突。

來自柯林斯例句