This is the 8717th most frequent Spanish word.
sinca
"Sinca" is not a standard Spanish word; it may refer to a brand name (Simca) or a regional/local term. Context is needed.
In this sentence, 'sinca' is used as a noun referring to a type of car model.
El sinca que compró Pedro era de color azul oscuro.
The Sinca that Pedro bought was dark blue.
Here, 'sinca' is used as a conjugation error, where the verb perhaps intended was 'caminar' ('camina').
Ella sinca por el parque todos los días para hacer ejercicio.
She walks briskly through the park every day for exercise.
In this case, 'sinca' specifies a subcategory of cars, retaining its noun usage.