The term "bastard" in slang is often used to describe someone who is perceived as unpleasant, mean, or untrustworthy. It can be employed in a lighthearted or humorous context among friends, but it can also carry a more serious connotation when used to insult someone. The word originally referred to a person born out of wedlock, but its meaning has evolved over time. In some contexts, "bastard" can also be used to express frustration or annoyance, as in phrases like "What a bastard!" when reacting to someone's actions. While it can be a strong term, its usage varies widely depending on the relationship between the speakers and the situation at hand.