knows stuff (adjective) veteran: experienced, seasoned
Sinonime: choleric,
cranky,
cross, excitable,
fiery, hot-tempered,
impatient,
impulsive, inflammable,
irascible, irritable,
passionate, peppery, petulant, quarrelsome, ratty,
sensitive, short-tempered, shrewish, splenetic,
temperamental, testy, waspish
Antonime: calm,
cool, easy-going, even-tempered,
laid-back