[from UNIX 'tar(1)']
vt. To create a
transportable archive from a group of files by first sticking them
together with 'tar(1)' (the Tape ARchiver) and then
compressing the result (see compress). The latter action is
dubbed 'feathering' by analogy to what you do with an airplane
propeller to decrease wind resistance, or with an oar to reduce
water resistance; smaller files, after all, slip through comm links
more easily.