I live in a dead end rural canyon in Los Angeles, which is very good for bird-watching.
But without Riahi, that transition might have come to a dead end.
They investigated and basically they were kind of at a dead end.
"closed end of a passage," 1886, from dead (adj.) + end (n.). Figurative use is attested from 1922. As an adjective, from 1928; as a verb, from 1921. Related: Deadender (by 1996).