This is the 2281st most frequent Russian word.
искусственный
Artificial.
Here, 'искусственное' (artificial) is used as an adjective to describe the lake as something made by human effort rather than occurring naturally.
Это искусственное озеро создано человеком.
This artificial lake was created by humans.
Here, 'искусственная' (artificial, feminine) is used to describe the smile, implying it lacked genuine emotion or was feigned.
Её улыбка показалась мне какой-то искусственной.
Her smile seemed somewhat artificial to me.
In this context, 'искусственный' (artificial) modifies 'интеллект' (intelligence), giving the compound term 'artificial intelligence,' which refers to intelligence demonstrated by machines.