ischuo denotes having the capacity or strength to do, endure, resist, or prevail in a stated situation.

Most often, the verb marks whether someone or something has sufficient capacity to carry out, endure, resist, or complete a specific action. It can also describe force that prevails or remains effective, and, in sayings contrasting the well and the sick, bodily strength or health.

1. Having sufficient capacity for an action · dominant

   In Acts 15:10, the speakers say that neither their fathers nor they could bear the yoke; in Acts 27:16, they gain control of the lifeboat only with difficulty. The same capacity is denied for such actions as hauling in a fish-filled net in John 21:6, finishing a building in Luke 14:29, answering a challenge in Luke 14:6, and keeping watch in Matthew 26:40.

   Acts 15:10Acts 27:16John 21:6Luke 14:29Luke 14:6Matthew 26:40
2. Exercising force or effectiveness · common

   In Acts 19:16, a man overpowers those he attacks, while Acts 19:20 describes the Lord's word as growing and prevailing. The present forms also occur where a covenant has force in Hebrews 9:17 and where the petition of a righteous person is described as powerful in James 5:16.

   Acts 19:16Acts 19:20Hebrews 9:17James 5:16Galatians 5:6Matthew 5:13
3. Being strong or well · rare

   The present active participle describes those who have no need of a physician in Matthew 9:12 and Mark 2:17, set against those who are sick. In these clauses, the term identifies persons characterized as strong rather than unable to act in a particular task.

   Matthew 9:12Mark 2:17

In the Anselm Project Bible: The APB variously presents the verb with “able,” “strong enough,” “prevail,” “force,” and “powerful.” These are best read as clause-level renderings of capacity, strength, or effectiveness rather than separate fixed English equivalents.