ironbark /ˈʌɪənbɑːk/ noun2 •(Australia) Any of several unrelated eucalypts that have dark, deeply furrowed bark. •(Australia) The hard wood of these trees, as used in building and construction.The tents and sheets are made of the best Canadian duck, tanned for the purpose of preservation with a strong extract of iron-bark and wattle-bark. — 1901 formsironbarks