An aromatic hydrocarbon in which at least one hydrogen atom on the ring is substituted by a group selected from the class consisting of unsubstituted or lower alkyl-substituted tricyclo[5.2.1.0.sup.2,6 ]dec-3-yl, tricyclo[5.2.1.0.sup.2,6 ]dec-4-yl, tetracyclo[6.2.1.1.sup.3,6.0.sup.2,7 ]dodec-4-yl and tetracyclo[6.2.1.1.sup.3,6.0.sup.2,7 ]dodec-5-yl groups, or its hydrogenation product.The compound is prepared by reacting an aromatic hydrocarbon having at least one hydrogen atom on the ring with a compound selected from the group consisting of unsubstituted or lower alkyl-substituted tricyclo[5.2.1.0.sup.2,6 ]dec-3-ene and tetracyclo[6.2.1.1.sup.3,6.0.sup.2,7 ]dodec-4-ene in the presence of a Friedel-Crafts catalyst, or hydrogenating the thus-obtained compound in the presence of a hydrogenation catalyst.The compound is useful as an additive for adhesives.