This is the 2097th most frequent Spanish word.
celular
Cell phone.
Here, 'celular' is used to refer to a mobile phone.
Mi celular no tiene señal en este lugar.
My cellphone has no signal in this area.
In this case, 'celular' is an adjective describing 'structures', meaning 'related to cells'.
Estudiamos las estructuras celulares en la clase de biología.
We study cellular structures in biology class.
The word 'celular' here is used as an adjective referring to technology related to cell communication.