This is the 16th most frequent Arabic word.
قد
The Arabic word "قد" is a particle that can indicate certainty ("indeed") or approximation/past tense ("has/have") depending on context.
'قد' here is used to indicate possibility in the context of the past.
قد ذهبت إلى السوق.
I might have gone to the market.
'قد' here is used to indicate possibility in the context of the present or future.
قد ينجح الطالب في الامتحان.
The student might succeed in the exam.
'لقد' is an emphatic particle used to assert the successful completion of an action in the past.