Realistic means sensible about what is actually possible. Be realistic, a realistic target, realistically speaking.
It is used to lower expectations politely — let us be realistic — and a realistic target is one that can actually be hit. The other sense is close to life in appearance: a realistic painting, realistic graphics. In art, realism is a specific movement and a broader approach. Note realistically, which usually introduces a concession; and that calling somebody unrealistic is a criticism of judgement rather than of hope.
1adjectiverealisticSensible about what is actually possible.
“You need to be realistic about how much you can afford to spend.”
2adjectivecloseClose to life in appearance.
“The dinosaur models in the museum are so realistic that small children are scared of them.”
realistic is a quality of practicality.
From realist + -ic.
Etymology from Wiktionary, CC BY-SA