The chlorine atom that is expelled as chloride ion accepts and electron pair from the S-Cl bond, but it does not make a new covalent bond, so it is neither electrophile or nucleophile. In this reaction, chloride ion is the leaving group . It has none of the features that would suggest it might behave as an electrophile. It has no lone pairs or areas of negative charge, suggesting it will not function as a nucleophile. This suggests that water can behave an a nucleophile.
Many molecules can be both nucleophiles and electrophiles.
How they behave depends upon what they react with. For example, if water is reacted with an electrophile, the water will behave as a nucleophile. Decide if each molecule or ion shown below will react as a nucleophile or electrophile, or both.