olemus
(2a) haagis: veoki järele haagitav mootorita abiveok
Wiktionary:
3. an unpowered wheeled vehicle, not a caravan or camper, that is towed behind another, and used to carry equipment, etc, that cannot be carried in the leading vehicle
https://en.wikipedia.org/wiki/Trailer_(vehicle)

(2b) treiler: raskeveohaagis
= heavy trailer
https://duckduckgo.com/?q=%22heavy+trailer%22&t=h_&iax=images&ia=images