Wordnet polsko-angielski 
                         (the older inactive central wood of a tree or woody plant
usually darker and denser than the surrounding sapwood) 
heartwood, duramen 
synonim: twardziel
synonim: twardzielec
synonim: inselberg
Nowoczesny słownik polsko-angielski 
                        inselberg
monadnock