This is the 6370th most frequent Russian word.
холодная
"Холодная" means "cold" (feminine form).
Here, 'холодная' acts as an adjective to describe the noun 'погода', referring to the cold weather condition.
Сегодня холодная погода.
Today the weather is cold.
In this sentence, 'холодное' is the masculine form of 'холодная', showing agreement with the noun 'утро' (morning) which is neuter.
Она надела пальто, потому что утро было холодное.
She put on a coat because the morning was cold.
In this example, 'холодный' is the masculine form of the adjective 'холодная' matching the masculine noun 'чай' (tea).