This word is from the Spanish seguro, meaning “certainly” or “definitely.”

In Filipino usage, a sigurista is someone who is careful to always make sure that everything goes according to plan. The keywords are “make sure.”

Sigurado ako.
I’m sure.

Ang kasalungat ng taong segurista ay taong mapusok.
The opposite of a prudent person is a rash person.
(Actually, the opposite of a sigurista is more like someone slapdash or doesn’t care much if things go as planned.)

Naniniguro ang sigurista na ang lahat ay wasto.
The prudent person makes sure that all is proper. 

Sigurado ang sigurista na ang lahat ay tama.
The prudent person is sure that everything is right.

Maging sigurista!
Be a prudent person!
= Act prudently!