- (literary)
like a ghost; connected with a ghost 鬼一般的；幽靈似的；鬼的；幽靈的 a spectral figure 鬼影
- (specialist)
connected with a spectrum 譜的；光譜的；頻譜的 spectral bands 光譜帶 the full spectral range 全光譜範圍
Word Originsense 1 early 19th cent.: from spectre + -al.sense 2 mid 19th cent.: from spectrum + -al.