Open English Wordnet
Adjectives
(a)weightyhaving relatively great weight; heavy“a weighty load”,
“a weighty package” (s)cogent, telling, weightypowerfully persuasive“a cogent argument”,
“a telling presentation”,
“a weighty argument” (s)grave, grievous, heavy, weightyof great gravity or crucial import; requiring serious thought“grave responsibilities”,
“faced a grave decision in a time of crisis”,
“a grievous fault”,
“heavy matters of state”,
“the weighty matters to be discussed at the peace conference” (s)weightyweighing heavily on the spirit; causing anxiety or worry“weighty problems”