If someone's way of speaking, writing, or behaving is portentous, they speak, write, or behave more seriously than necessary because they want to impress other people. 自命不凡的; 装腔作势的
adjective [原级]不祥的;预兆的;令人惊讶的
There was nothing portentous or solemn about him. He was bubbling with humour. 他身上一点也不装腔作势或故作严肃。他幽默十足。
portentous
“ -ous” ⌜ 表示具有某种性质的 - indicating having the quality of ~ ⌟