Final answer:
The word 'merciful' is an adjective that describes someone who shows compassion, forgiveness, and kindness.
Step-by-step explanation:
Merciful is an adjective that describes someone who shows compassion, forgiveness, and kindness. It is formed using the suffix -ful, which means full of or characterized by. For example, when we add -ful to the word mercy, we get merciful, which means full of mercy. A sentence using this word could be: 'She showed a merciful act by forgiving her friend's mistake.'