hard to define

See: elusive
References in classic literature ?
But Anne thought she liked his face; it was kind and honest and tender; there was something else in it, too -- just what, Anne found it hard to define.
On the matter of simplicity Doyo was advocating/recommending, this is one virtue hard to define not only on Christmas but during celebrations, fiestas, birthdays, weddings, etc.
It's hard to define Nomadic with one word, and I love that.
Research had highlighted that bullying was hard to define.
And what next will our scientists find Great distances and time are still hard to define Problems we must resolve for the future of mankind, Soon the new telescope will be empowered And with new knowledge we could be showered Billions and billions of more miles we will see, We may discover mankind's destiny Still we will have to cross new frontiers, No doubt this journey will shed many tears This dream we have will one day come true But it will not involve the likes of me or you.
Asked whether he thought there was a "war between the West and Islam itself," Trump said in his usual obscure phraseology: "It's radical, but it's very hard to define.
It's always a clever move to get people to admire you for something abstract and hard to define - Damien Hirst has made a lucrative career out of it.
Cork boss Brian Cuthbert said: "It's hard to define how much [it affected us].
It requires great singing (which must sound effortless), immaculate comic timing and a rather hard to define Frenchness and sexiness.
There is not much snow in Europe now, and many events are being posponed, so it is hard to define the exact day of the tournament's start," the coach said.
It's as much about love and moving on in life as it is about a marriage's failure and gruesome results: hard to define, suffice to say that it's an intriguing story indeed.
Welcoming the additional research, water consultant Philip Pells, said : "it's very hard to define the impact if you don t know what the starting point is.