a newcomer; a new member or recruit (someone recently joined), sometimes with a slightly dismissive nuance.
彼はこのサークルの新参だが、積極的に活動している。
He is a newcomer to this club, but he's actively participating.
古参のメンバーが新参をあまり歓迎していないようだ。
It seems the long-standing members aren't very welcoming of the newcomers.
新参者としてまずは挨拶をして回った。
As a newcomer, I went around introducing myself first.