The United States Holocaust Memorial Museum:

The acts that constitute genocide fall into five categories:

• Killing members of the group
• Causing serious bodily or mental harm to members of the group
• Deliberately inflicting on the group conditions of life calculated to bring about its physical destruction, in whole or in part
• Imposing measures intended to prevent births within the group
• Forcibly transferring children of the group to another group

https://www.ushmm.org/genocide-prevention/learn-about-genocide-and-other-mass-atrocities/what-is-genocide

A short list of official allegations of Israel’s genocide against Palestinians (Google):

South Africa's genocide case against Israel

The International Court of Justice (ICJ) has ordered Israel to prevent the destruction of evidence and ensure the preservation of evidence related to allegations of genocide against Palestinians in Gaza.

Israel's use of the "Hannibal Directive"

Israel has been accused of using its "Hannibal Directive" policy, which allows for the killing of Israeli soldiers and civilians to prevent them from being taken alive as prisoners of war. This policy has been criticized as a form of genocide.

UN reports

UN experts have reported "grave violations" committed by Israeli forces against Palestinians in Gaza, including "genocidal incitement" and the use of "powerful weaponry with inherently indiscriminate impacts." They have also cited evidence of Israel's intent to "destroy the Palestinian people under occupation."

Special Rapporteur's findings

The UN Special Rapporteur on the situation of human rights in the Occupied Palestinian Territories, Francesca Albanese, has found "reasonable grounds" to believe that Israel is committing genocide against Palestinians in Gaza. She cited evidence of Israel's intent to destroy the Palestinian group, including causing serious bodily or mental harm, imposing conditions of life calculated to bring about physical destruction, and preventing births within the group.

Amnesty International's research

Amnesty International has gathered evidence of unlawful Israeli attacks in Gaza, resulting in mass civilian casualties. The organization has criticized Israel's failure to distinguish between military objectives and civilian objects, leading to indiscriminate attacks that are war crimes.

Other reports and allegations

Various independent reports and allegations have been made about Israel's treatment of Palestinians, including forced transfers, torture, and the destruction of infrastructure. Some have characterized Israel's actions as genocide, while others have criticized the use of the term without sufficient evidence.