Thank you Siunia for making it accessible to the forum people; it's ever so useful to a learner. 'They' is extremely commonly used in the definitions of words, particularly in dictionaries. I use 'they' quite a lot when don't know a sex or when it's not important to me, because continuously using 'he-or-she' is a cliche-ridden style, so to speak. Males are still favoured in English, though, aren't they?