1.
new entry, newly joined
Describes someone who has recently entered or joined an organization, school, or group. Almost always used as a modifier before another noun.
新入社員の研修が始まった。
The training for new employees has started.
新入生を歓迎するパーティーを開いた。
We held a party to welcome the new students.
今年の新入部員は去年より多く、活気がある。
This year's new club members are more numerous than last year, and there's a lot of energy.
新入 means newly entering or newly joined. It is used almost exclusively as a prefix modifying another noun — it rarely stands alone.
COMMON COMPOUNDS:
- 新入社員: new employee (often abbreviated 新入社員 → 新社員)
- 新入生: new student (entering a school)
- 新入部員: new club member
- 新入会員: new member (of an organization)
CONTRAST:
- 新入: newly joined (prefix, always modifies a noun)
- 新人: newcomer, rookie (can stand alone as a noun)
- 入社: joining a company (the act itself)
SEASONAL CONTEXT:
In Japan, the school and fiscal year begin in April. 新入生 and 新入社員 are most commonly heard in spring.