slow and awkward because of being very heavy or large (Cambridge)
too slow and careful; serious and boring (Oxford)
بیوقوف ,احمق
He had a slow and ponderous manner .(Cambridge).
He spoke in a slow ponderous voice .(Oxford)
a slow and ponderous manner
a slow ponderous voice
Awkward
Clumsy
Bulky
Elegant
Graceful
Ponderousness
Ponderously