having an indifferent, unconcerned manner
Despite the fact that everyone in the lab was rushing like mad to meet the deadline, the project leader remained calm and insouciant.
insouciant: sounds like In-soup-ant or in-sauce-ant. Suppose the waiter serves you a soup with an ant in it and he is not even concerned about removing it, is insouciant. in+social. when a person is not social it means he does not care about people around him