Someone or an animal (ma-) is cunning, stealthful.
Ilo. sídap 'sharp (knife, intellect), keen'
Masidap a mangamet so pyek posak na.
His cat is stealthful at catching chicks.
Someone (mag-) cunningly does something (i-), especially to deceive someone (-an).
Magsidap ka tan dyi ka manaho.
You cunningly do (something) so that you are not hit.