Kitāb al-Tawḥīd - Salih Al-Fawzan - (35)

and the term ḍalāl is used in several ways:

Sometimes it denotes outright unbelief. Allah says, “Whoever disbelieves in Allah, His angels, His scriptures, His messengers, and the Last Day has truly strayed into deep misguidance” (al-Nisāʾ 4:136).
Sometimes it is applied to polytheism. Allah says, “Whoever associates others with Allah has certainly gone far astray” (al-Nisāʾ 4:116).
At other times it refers to deviation that falls short of unbelief—hence the expression “deviant sects,” meaning groups that have diverged from the truth.
It can also mean committing an error, as in the words of Moses: “I did it then while I was among the erring” (al-Shuʿarāʾ 26:20).
Finally, it may be used for forgetfulness, as in His statement: “so that if one of them forgets, the other may remind her” (al-Baqarah 2:282).

والضلال يطلق على عدة معان: ١ - فتارة يطلق على الكفر، قال تعالى: ﴿وَمَنْ يَكْفُرْ بِاللَّهِ وَمَلَائِكَتِهِ وَكُتُبِهِ وَرُسُلِهِ وَالْيَوْمِ الْآخِرِ فَقَدْ ضَلَّ ضَلَالًا بَعِيدًا﴾ [النساء: ١٣٦] ٢ - وتارة يطلق على الشرك، قال تعالى: ﴿وَمَنْ يُشْرِكْ بِاللَّهِ فَقَدْ ضَلَّ ضَلَالًا بَعِيدًا﴾ [النساء: ١١٦] ٣ - وتارة يطلق على المخالفة التي هي دون الكفر - كما يقال: الفرق الضالة أي المخالفة. ٤ - وتارة يطلق على الخطأ، ومنه قول موسى ﵇: ﴿قَالَ فَعَلْتُهَا إِذًا وَأَنَا مِنَ الضَّالِّينَ﴾ [الشعراء: ٢٠] ٥ - وتارة يطلق على النسيان، ومنه قوله تعالى: ﴿أَنْ تَضِلَّ إِحْدَاهُمَا فَتُذَكِّرَ إِحْدَاهُمَا الْأُخْرَى﴾ [البقرة: ٢٨٢]