propolis
Concise Oxford English Dictionary © 2008 Oxford University Press:
propolis /ˈprɒpəlɪs/
▶noun a red or brown resinous substance collected by honeybees from tree buds for constructing and varnishing honeycombs.
– origin C17: via L. from Gk propolis ‘suburb’, also ‘bee glue’, from pro ‘before’ + polis ‘city’.
'propolis' also found in these Oxford entries:

