Parsing inflected forms may not always work as expected. If the following does not give the correct word, try Latin Words or Perseus.
dē-māno, āvi, 1,
dī-māno (dem-), āre, v. n., to flow different ways, to spread abroad (very rare): meus hic forensis labor dimanavit ad existimationem hominum paulo latius, Cic. Cael. 3, 6.