This is the 156th most frequent Spanish word.
largo
Long.
In this sentence, 'largo' is used as an adjective to describe the extent of the path's length.
El camino hacia el parque es muy largo.
The path to the park is very long.
Here, 'larga' (feminine form of 'largo') describes the prolonged duration of the meeting.
La reunión fue larga y agotadora.
The meeting was lengthy and exhausting.
In this context, 'largo' describes the excessive length of the pants in relation to fit.