Good.
So we want s " designates " to actually know one of the constituents which acts like a head in some respects but is sort of , um , really important for say composition later on. So for instance , if some other construction says , you know , " are you of type  is this part of type whatever " , um , the " designates " tells you which sort of part is the meaning part. OK , so if you have like " the big red ball " , you know , you wanna know if there 's an object or a noun. Well , ball is going to be the designated sort of element of that kind of phrase.
Mmm.
Um , there is a slight complication here which is that when we talk about form it 's useful sometimes to talk about , um  to talk about there also being a designated object and we think that that 'll be the same one , right ? So the ball is the head of the phrase , " the r the  " , um , " big red ball " , and the entity denoted by the word " ball " is sort of the semantic head in some ways of  of this sort of , um , in interesting larger element.