weighty

1 ENTRIES FOUND:
weighty /ˈweɪti/ adjective
weightier; weightiest
weighty
/ˈweɪti/
adjective
weightier; weightiest
Britannica Dictionary definition of WEIGHTY
[also more weighty; most weighty]
1 
: having a lot of weight : heavy
2 
: very important and serious
3 
: having the power to influence the opinions of other people

— weightiness

/ˈweɪtinəs/ noun [noncount]