boarder has definitions from the fields of education,nautical
1
[ noun ] (nautical) someone who forces their way aboard ship

Examples

"stand by to repel boarders"

Related terms

intruder board

2
[ noun ] a tenant in someone's house

Synonyms

roomer lodger

Related terms

tenant board

3
[ noun ] (education) a pupil who lives at school during term time

Related terms

schoolchild board

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