Sticky

adherente

(able or likely to stick)

adherible

(able or likely to stick)

bochornoso

(of weather)

escabroso

(potentially difficult to escape from)

exitoso

(that keeps visitors from leaving it)

pegajoso

(able or likely to stick)

pegajoso

(that keeps visitors from leaving it)

peliagudo

(potentially difficult to escape from)

popular

(that keeps visitors from leaving it)

predeterminado

(persistent across multiple incarnations of a widget)

recado adherible

(sticky note, such as a Post-It)