1. A reference to a person, thing, or idea that is vague, ambiguous, or not sufficiently clear to be easily understood
The pronoun 'it' in that sentence is an unclear reference because readers cannot determine which noun it refers to.
O pronome 'ele' naquela frase é uma referência ambígua porque os leitores não conseguem determinar a qual substantivo se refere.
2. In writing or communication, a situation where the connection between a reference and what it refers to is not immediately apparent or obvious
The essay contains an unclear reference to a previous study that was never properly introduced.
O ensaio contém uma referência imprecisa a um estudo anterior que nunca foi adequadamente apresentado.