The words that carry a negative connotation from the provided list are:
- zealot
- truancy
"Zealot" often refers to someone who is overly passionate or extreme in their beliefs, which can have a negative implication. "Truancy" refers to the act of staying away from school without permission, which is generally viewed negatively.
"Sustain" and "phenomenon" do not carry negative connotations; "sustain" is neutral or positive in the context of maintaining or supporting something, and "phenomenon" is neutral, referring to any observable event or fact.