pero

1. (of a bird) feather
   Na terasi smo našli belo golubije pero. — We found a white pigeon feather on the balcony.
   Iz jastuka je ispalo jedno guščje pero. — A goose feather fell out of the pillow.
2. (for writing with ink) pen; quill
   Deda je pisma pisao perom i mastilom. — Grandpa wrote letters with a pen and ink.
3. formal (of a writer, style) pen; writing style; writer
   Taj novinar ima veoma oštro pero. — That journalist has a very sharp pen.
   Bio je čovek od pera, a ne od akcije. — He was a man of letters, not of action.
4. (of a fountain pen) nib
   Pero na nalivperu se savilo i više ne piše lepo. — The nib on the fountain pen got bent and no longer writes well.

An ordinary ballpoint pen is "hemijska (olovka)"; "olovka" on its own usually means a pencil; a fountain pen is "nalivpero".