complex; complicated; intricate; mixed (feelings)
plural; multiple; several
reproduction; duplication; reprinting
composite; combined; complex
duplication; repetition; overlapping; redundancy; restoration
copy; reproduction; replica; facsimile
two-seater (e.g. aircraft)
multi-layered; multi-tiered; multi-storied
double track; two-track line
double-entry (e.g. bookkeeping)
complex; complex (number)
four-track rail line (two in each direction); quadruple railway track
compound note (on a harmonica)
multiple lines (of text, code, etc.)
two-character surname (in China); compound surname; family name consisting of two combined names (in ancient Japan)
complex sentence; sentence with an independent clause and at least one dependent clause
double refraction; birefringence
double decomposition; metathesis
double-crosspiece cross (symbol for tuberculosis prevention)
compound umbellate inflorescence; compound umbel
doubles (tennis, badminton, etc.)
double sign; plus-minus sign; plus or minus sign
multiple parallel fermentation (esp. in sake brewing)
compound ratio; cross ratio; compound proportion