machin
/ma.ʃɛ̃/
1.
nounmasculine
thingy; whatchamacallit; a vague or unspecified object
2.
nounmasculine
what's‑his‑name / so‑and‑so; a placeholder for a person whose name is forgotten or not specified
J'ai croisé machin dans la rue, mais j'ai oublié son prénom.
I ran into what's‑his‑name in the street, but I forgot his first name.
Synonyms:untel, truc, trucmuche
